Hello, I Have A Cadet 150-B Its Made By Mada It Has Four 22jg6 Tubes That Are Not Original These Are Much Cheaper.Anyway It Has A Bad Hum When Keyed-Up I Cant Find Any Info On This Amp. With My Connex 4300 hp It Will Dead Key 20 Wats And Swing 240 I Think This Is A Modulator No High Or Low Switch Just Tune And Load. Thanks For Any Info About This Amp And How To Repair It Thanks Again.